The number of diagnosed cases of diabetes continues to increase in the U.S. and throughout the world, creating enormous economic and public health consequences. One area in which recently developed technologies have been able to improve the standard of care has been in the maintenance of tight control over the blood glucose levels. It is well known that if a diabetic patient's blood glucose values are maintained within the normal range of from about 80 milligrams per deciliter (mg/dL) to about 120 mg/dL, the physiologically damaging consequences of unchecked diabetes can be minimized.
Recent technological and commercial development in the two areas of glucose monitoring and of insulin administration have each contributed significantly to improving the ability of diabetic people to maintain better control over their blood glucose level, and thereby enhance their quality of life.
With better blood glucose information, diabetic patients can better exercise tight control of their blood glucose level through a variety of means, including diet, exercise, and medication. A common type of glucose measuring device is represented by hand-held electronic meters which receive blood samples via enzyme-based “test strips”. In using these systems, the patient lances a finger or alternate body site to obtain a blood sample, the sample is applied to the strip, the strip is inserted into a port in the meter housing where it engages the meter's internal electronics, and the electronics convert a current generated by the enzymatic reaction in the test strip to a blood glucose value. The glucose value is then typically displayed on the meter's liquid crystal display (LCD), which is generally relatively large in size in order to accommodate the eyesight capability of older adults and diabetic people, who often have deteriorating vision.
Some diabetic patients require insulin administration in order to maintain tight control of their glucose level. Insulin administration to these insulin-dependent patients has traditionally been by self-injection, but a more recently available technology is represented by insulin pumps. These pump devices offer significant therapeutic value over self injection, as the pumps deliver insulin in a more physiological manner, with measured doses of insulin being infused slowly, over an extended period of time. Further, the rate at which insulin is delivered can be programmed to follow standard or individually-modified protocols, to give the user even better glucose control over the course of a day. Insulin pumps have commercially evolved to become small in size, which offers easier portability and unobtrusiveness, and with electronic advances, they have evolved to become more fully-featured, and thus capable of enhanced and individualized performance. These various advantages in terms of health care quality and user convenience have supported the growth of the insulin pump market.
It has been recognized that combining the newer technologies of insulin administration with the newer technologies of glucose measurement could significantly improve user convenience, resulting in a greater ability to comply with frequent testing, and greater ability to effect individually appropriate schedules of insulin administration.
Such an integrated combination of a glucose measuring device and insulin pump is shown in U.S. Pat. No. 5,665,065, which teaches the inclusion of a mechanism for measuring blood glucose within the housing of an insulin pump. While the advantages of such a glucose measuring/insulin pump combinations has been known for many years, in fact, no such device has become commercially available. Various practical and market-based factors may contribute to the absence of a combination device in the market. Insulin pumps, though expensive, have become well established and stabilized in the market; and pump users tend to remain with their initial choice. Glucose meters, in contrast, are presently evolving more quickly and are inexpensive for users; indeed they are often provided to users by manufacturers without charge, as a loss leader in an overall business strategy. At least in part as a consequence of the low price, glucose meter users have lower brand loyalty, and will switch among brands. As another consequence, there is intense manufacturing cost pressure on glucose meters, which, in turn, encourages efficient product design by the meter manufacturers. From the perspective of a pump manufacturer in designing such a physically integrated combination device, the manufacturer would need to commit to a particular blood glucose measuring technology in the face of the concern that such technology could become less competitive or even obsolete during the normal life of the pump product.
It is known that hand-held glucose meters can advantageously be manufactured to include short range wireless communication capability, through which data from the glucose sensor can be transmitted to another health device, such as a computer, cell phone, or a personal digital assistant (PDA); such wireless communication between two portable devices is shown in the PCT publication WO03005891A1. This wireless data transfer relieves the glucose sensor user of the need to record such data by hand, and allows for accumulation of data points within a larger database for longer term health monitoring and intervention. In spite of the benefits of wireless communication, the inconvenience of handling separate devices to achieve the patient's singular goal of maintaining glucose control remains unsolved by wireless communication alone.
Devices that provide for secure personal portability of various communication and health-related electronic devices, and ease of use while being carried are also well known. Holsters and cases for electronic devices that attach to belts or other articles of clothing are never far from where mobile telephones are being sold, and are described in U.S. Pat. Nos. 5,664,292 and 5,833,100, and 6,081,695. Similarly, U.S. Pat. No. 5,472,317 describes an apparatus that provides for a belt-clip mounting for a medication infusion pump.
In view of these various problematic factors associated with the actual physical integration of a glucose measuring device with an insulin pump, it would be desirable to provide an insulin pump user the benefits and performance of functionally combined glucose measuring device and insulin pump. Such a combined device would desirably be in a portable configuration that, in fact, maintains physical distinctness of the devices, gets past the market-based barriers that accompany physical integration, and yet offers a combination which for all practical purposes is used as a single integrated device. It would be further desirable for this functionally integrated device to be fully enabled to interact with other devices within a personal area network.